Exhaust Collectors and line.

[MELIS THIBAUD]

Hi guys.
I'm self making my exhaust line and collectors...

I've already done some tests. It is very hard

I'm trying to do each line as the same lenght... but is it really useful ?
On the pictures the 4 in 1 is just a provisory assembling (i ve buy two ready mades one)

my first try: the line were not at the same lenght and too angled not curved so i've retry

My second try was better but too large and too close from the wheel so i've retry again

My third try has the same lenght for each line. But the one for cylinder number 8 has a disgusting design.

I've looking hundreds of pictures... there are not two exhaust scheme same. a majority does not seem to have the same distance


I'm asking myself... the line need to be the same lenght as is opposit... not necessary all the line. ???

My question is: Is it necessary ? What difference ?

 

[Mark H.]

Search the web for "Headers by Ed". Some good info there. I built an equal length set for my 1965 GT350 race car some 30 years ago. What an ordeal to make it all fit, on and off many, many times. But I can tell you my plugs all look identical! After years of racing trying staggered jetting, dual/single plane madifolds, different headers; Hooker, Sanderson, tri-wye, JBA, different fuel, etc... my motors have never ran better, cleaner, cooler... with more lowend torque and RPM. Have no dyno info, but temps on each cylinder are all within some 20 degrees. Depending on your firing order I think you can gain some real improvement by ensuring one cylinder is not immediately following another in the same collector, like 7/8 in a 289. You can use PVC piping or the expensive plastic mock up header pieces, save you some metal fab? I think equal length is one thing, but actual flow and sound waves are another. Bends and curves increase restriction which may equal out flows in a longer less restrictive tube. If I had to do again might not be so concerned with the last 1" or so. All a black art, but it's fun doing it yourself! Good luck.

 

[Randy V]

Ed has been a very good friend for roughly 50 years. He knows more about what it takes to make power through breathing than anyone I have ever heard about. I’ve not talked with him now for roughly 10 years - life seems to get in the way of that.
Thanks for the reminder - I think I’ll give him a call….

Welcome to the Home Page of HEADERS BY "ED", INC. May you learn a lot as you go through our website!

 

[Ole Nylende]

Well. The original ones obviously were not 100% equal length based on the picture from the parts catalogue.

It is hard to tell exactly how much infuence it will have on your end result. It might be that the extra backpressure your add in terms of bends and weldsbeads is worse than a small deviation to the tuned length.
I doubt that you ran your setup in pipe max or similar in order to get the most suitable tuned length, so error 1 started there i guess?

Personally i would not put that much effort into getting them equal if it generates alot of hazzle. It is not like the last 0,1hp gain is something you will notice with the butt dyno.

 

[JP Verweij]

Indeed, non of the GT40s share the same exhaust.
Took loads of pics at Spa Six Hours.
Most importand thing to consider with your design, make sure your sparkplugs are easy accesable and sparkplug boots have enough clearance.

Have seen GT40s where the exhaust had to come off to change a sparkplug.

 

[Morten]

Atleast its easier access on these GT40s than any other new car where you need to lower the engine to change a lightbulb.

 

[Michael]

“Perfection is the enemy of progress”
Winston Churchill

 

[MELIS THIBAUD]

After many days to think about... i preferred aesthetics to performance...
So i've build a not equal lenght pipes
That is my own design

(just need to modificate pipe N°5 cause it has a little strabismus)

 

[Mark H.]

Looks like you can get to the plugs easily. Wires too? Can you get the v/c off? What firing order? Looks like you separated 7 and 8 to opposed collectors? Looks cool!

 

[MELIS THIBAUD]

i would like a "spider" kind design
Yes i've done a cross over shape... so 6 and 7 are pluged on the opposite collector (also 2 and 3)
Wires and spark plugs are easily removable. My fire order is 15426378.

I don't know what is v/c ... sorry i'm french i don't have all the englis abbreviations.
thanks for your encouragement

 

[Mark H.]

V/C = Valve cover

 

[MELIS THIBAUD]

Oh ok. Yes V/c is removable